Secure Erase on D2200sb Storage Blade

Hello,I have DAS storage D2200sb attached to my exchange server i.e. HP Blade G7. All the exchange data is residing on the attached storage blade (RAID5 with P410i smart controller) . I use HP Array Configuration Utility for RAID config. I want to know what is the best way to do a manual secure data erase/wipe on data that is residing on the attach storage blade so that the data is unrecoverable in any scenario.